Ceramic heaters are used in such applications as heat source for starting an engine, auxiliary heat source for room air heater and heater of air-fuel ratio sensor. An example of ceramic heater used in these applications is a ceramic heater that has such a constitution as shown in Patent Document 1, where a heating resistor is embedded in a ceramic base, and a lead is connected via a brazing material to an external electrode (electrode pad) that is electrically connected to the end of the heating resistor.    Patent Document 1: Japanese Unexamined Patent Publication (Kokai) No. 2005-332502